Two-dimensional transducer arrays for improved field of view

ABSTRACT

A method and system for using two-dimensional transducer arrays for improving the field of view during an ultrasonic examination are disclosed. The ultrasonic imaging system includes a two-dimensional transducer array with a plurality of acoustic elements, a beam controller, a signal processor, and a display. The beam controller controls a generated acoustic beam capable of being advanced longitudinally or laterally along the two-dimensional transducer array. Additionally, the generated acoustic beam is capable of being phase-shifted by the beam controller. Combining the phase shifting of and advancement of the acoustic beam increases the field of view of the two-dimensional array.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. provisional application Ser. No.60/483,797 filed Jun. 30, 2003, which is incorporated herein byreference.

The present invention relates generally to transducers. Morespecifically, it relates to ultrasonic imaging systems usingtwo-dimensional ultrasonic transducer arrays having an improved field ofview.

Ultrasonic transducers are used in many medical applications and, inparticular, for the non-invasive acquisition of images of organs andconditions within a patient, typical examples being the ultrasonicimaging of fetuses and the heart. The ultrasonic transducers used insuch applications are generally hand held, and must meet stringentdimensional constraints in order to acquire the desired images. It isfrequently necessary that the transducer be able to obtain highresolution images of particular portions of a patient's body when usingendoscopic ultrasonic imaging equipment.

Typically, conventional ultrasonic imaging equipment use two-dimensionalarrays for acquiring the ultrasonic images of particular tissues ororgans within the patient's body. Generally, these arrays include aplurality of acoustic elements arranged in a planar configuration. Beamsteering is used in such systems to control the propagation of thedirection of the ultrasonic beam. Employing this method allowsultrasonic systems to acquire images of the particular region of thepatient's body.

However, conventional ultrasonic systems have a limited field of viewdue to the limitations at the beam steering end due to the planararrangement of the acoustic elements. Therefore, a need exists for animproved ultrasonic array for use with conventional ultrasonic imagingsystems.

It is an object of the present invention is to provide an ultrasonicimaging system having improved volumetric imaging.

Another object of the present invention to provide an ultrasonic imagingsystem having an increased field of view.

Yet another object of the present invention is to provide an ultrasonicimaging system with improved ergonomic characteristics.

A further object of the present invention is to provide an ultrasonicimaging system that has particular characteristics of its acoustic pulsecontrolled by electronics in the ultrasonic imaging system.

An ultrasonic imaging apparatus having improved field of view forimproved volumetric imaging is hereinafter disclosed. In particular, theapparatus includes an ultrasonic probe and a plurality of acousticelements configured and arranged to form a two-dimensional array. Thetwo-dimensional array is further configured and adapted to fit withinthe housing and each of the acoustic elements is capable of generatingan acoustic pulse and/or receiving an echo signal. Further included inthe apparatus is a beam controller coupled to the two-dimensional arrayand capable of driving at least one of the acoustic elements, therebyproducing an acoustic pulse for impinging an acoustic target, andpreferably activating a plurality of acoustic elements to form anacoustic beam. The acoustic target reflects at least a portion of theacoustic beam as at least one echo signal. The beam controller furtherincludes associated circuitry capable of controlling directionalmovement of the acoustic beam. A signal processor is coupled to thetwo-dimensional array for processing at least one echo signal to form atleast one image signal. A display operatively coupled to the signalprocessor is further included for displaying data corresponding to theat least one image signal.

Additionally, a method for improving the field of view, therebyimproving the volumetric imaging in an ultrasonic imaging apparatus ishereinafter disclosed. The method includes providing an ultrasonic probehaving a plurality of acoustic elements configured and arranged to forma two-dimensional array that is configured and adapted to fit within theultrasonic probe. Each of the acoustic elements is capable of generatingan acoustic pulse and/or receiving an echo signal. A beam controllercoupled to said two-dimensional array is provided where the beamcontroller is capable of driving at least one of the acoustic elementsto produce the acoustic pulse for impinging an acoustic target togenerate at least one echo signal. Preferably, the beam controlleractivates a plurality of acoustic elements to form an acoustic beam.Further still, the beam controller has associated circuitry capable ofcontrolling directional movement of the acoustic beam, and a signalprocessor coupled to the two-dimensional array for processing at leastone echo signal, thereby forming at least one image signal. Theultrasonic imaging system processes at least one echo signal to form atleast one image signal and is capable of displaying data correspondingto the at least one image signal on a display.

Further disclosed is an ultrasonic imaging kit that includes at leasttwo ultrasonic probes configured and dimensioned for alternativeplacement within the ultrasonic imaging system. Each ultrasonic probeincludes a transducer assembly with an interface for communicating withcircuitry of the ultrasonic probe. Each transducer assembly furtherincludes a plurality of acoustic elements configured and arranged toform a two-dimensional array and the two-dimensional array is configuredand adapted to fit within the ultrasonic probe. It is preferred that atleast two ultrasonic probes are provided where at least one of theultrasonic probes has a different transducer assembly from at least oneother ultrasonic probe. Each of the acoustic elements is capable ofgenerating an acoustic pulse and/or receiving an echo signal. The beamcontroller is coupled to the two-dimensional array and is capable ofdriving at least one of the acoustic elements to produce the acousticpulse for impinging an acoustic target and generating at least one echosignal, and preferably driving a plurality of acoustic elements to forman acoustic beam. The beam controller has associated circuitry capableof controlling directional movement of the acoustic beam and a signalprocessor coupled to the two-dimensional array for processing at leastone echo signal, thereby forming at least one image signal. The displayis capable of displaying data representing the at least one imagesignal.

An ultrasonic imaging system having improved field of view for improvedvolumetric imaging is hereinafter disclosed and includes an ultrasonicprobe, a plurality of acoustic elements configured and arranged to forma two-dimensional array that is configured and adapted to fit within theultrasonic probe. Each of the acoustic elements is capable of generatingan acoustic pulse and/or receiving an echo signal. Coupled to thetwo-dimensional array is a beam controller that is capable of driving atleast one of the acoustic elements to produce the acoustic pulse forimpinging an acoustic target, thereby generating at least one echosignal. The beam controller has associated circuitry capable ofcontrolling directional movement of the acoustic pulse is operativelycoupled to the transmitter and communicates with a signal processorcoupled to said two-dimensional array for processing at least one echosignal, thereby forming at least one image signal where the display iscapable of displaying data corresponding to the at least one imagesignal. A means for connecting the housing to an ultrasonic imagingapparatus is further included.

The foregoing objects and advantages of the present invention may bemore readily understood by one skilled in the art with reference beinghad to the following detailed description of preferred embodimentsthereof, taken in conjunction with the accompanying drawings in which:

FIG. 1 is an ultrasonic imaging system with a prior art two-dimensionalarray having acoustic beam steering;

FIG. 2 is an ultrasonic imaging system with a two-dimensional arrayincluding acoustic beam tractor treading according to an embodiment ofthe present disclosure;

FIG. 2 a is an ultrasonic imaging system with a two-dimensional arrayhaving acoustic beam steering and beam tractor treading according to anembodiment of the present disclosure;

FIG. 3 is an ultrasonic imaging system with a two-dimensional arrayhaving a combination of acoustic beam steering and acoustic beam tractortreading according to another embodiment of the present disclosure;

FIG. 4 is an ultrasonic imaging system with a cylindricaltwo-dimensional array having acoustic beam steering and acoustic tractortreading according to a further embodiment of the present disclosure;and

FIG. 5 is an ultrasonic imaging system with a convex two-dimensionalarray having acoustic tractor treading according to a further embodimentof the present disclosure.

Several embodiments of the present invention are hereby disclosed in theaccompanying description in conjunction with the figures. Preferredembodiments of the present invention will now be described in detailwith reference to the figures wherein like reference numerals identifysimilar or identical elements. As used herein, the term “distal” refersto that portion of the tool, or component thereof which is further fromthe user while the term “proximal” refers to that portion of the tool orcomponent thereof which is closer to the user.

An example of an ultrasonic imaging system using a conventionalultrasonic transducer array is illustrated in FIG. 1. An ultrasonicprobe 20 includes a conventional two-dimensional ultrasonic transducerarray 10 (see FIG. 1) with a plurality of acoustic elements 12 arrangedin a number of columns and rows. These acoustic elements 12 areconfigured and arranged in a generally planar configuration. Eachacoustic element 12 is formed from a suitable piezoelectric material andis capable of generating an acoustic pulse 8 at a particular frequencywhen a driver signal is applied to the acoustic element 12. Thegenerated acoustic pulse 8 impinges on an acoustic target where at leastsome of the energy in the acoustic pulse 8 is reflected back towards theacoustic element 12 as an echo signal 6. In addition, each acousticelement 12 is capable of receiving the echo signal 6 from the acoustictarget and generating a corresponding output signal. Conventionalultrasonic imaging systems have a beam controller 40 for generating thedriver signal 25 and for electronically steering the acoustic pulse 8(“beam steering”).

Two-dimensional transducer arrays 10 are generally employed withaccompanying circuitry to produce three-dimensional ultrasonic images ofthe acoustic target since the acoustic beam 30 is generated by acousticelements 12 in both the rows and the columns of the two-dimensionaltransducer array 10. By controlling the phase differential, or the timedelay, among the acoustic elements 12 that are driven by the beamcontroller 40 (i.e. phase-shifting), a number of acoustic pulses 8 arecombined into an acoustic beam 30, that can be electronically steered bythe beam controller 40 in both directions A and B (represented bydouble-ended arrows A and B in FIG. 1) to acquire acoustic targetswithin the field of view of the ultrasonic transducer array 10 (i.e.“beam steering”). However, conventional two-dimensional ultrasonictransducer arrays 10 have limited fields of view along with a relativelysmall acquired volume 14 that is close the surface of the ultrasonictransducer array 10, shown as the acquired volume 14 in FIG. 1. Inaddition, ultrasonic imaging systems further include a signal processor50 and a display 60.

Ultrasonic imaging systems according to an embodiment of the presentinvention are shown in FIGS. 2 and 2 a, and further described withspecificity hereinafter. Referring first to FIG. 2, the ultrasonicimaging system includes an ultrasonic probe 220 with a two-dimensionaltransducer array 210, a beam controller 240, a signal processor 250, anda display 260. A plurality of acoustic elements 212 is disposed in anumber of rows and columns to form the two-dimensional transducer array210. In the presently disclosed two-dimensional transducer array 210,the acoustic pulses 208 are generated by acoustic elements 212 in thetwo-dimensional transducer array 210 to form an acoustic beam 230. Thebeam controller 240 is coupled by a connecting means 225 to the acousticelements 212 of the two-dimensional transducer array 210 and generates adriver signal 227 that is communicated to one or more of the acousticelements 212. Each of the acoustic elements 212 is formed from asuitable piezoelectric material and is capable of generating an acousticpulse 208 and receiving an echo signal 206. It is contemplated that anumber of the acoustic elements 212 may be “passive” elements (i.e. notconfigured for generating acoustic pulses or receiving echo signals)while the remaining acoustic elements 212 are “active” elements (i.e.configured for generating an acoustic pulse 208 and receiving an echo206).

The connecting means 225 is generally a cable including a plurality ofconducting elements, such as wires. Alternatively, the connecting means225 can be significantly improved if some of the electronics are locatedin the ultrasonic probe housing and the connecting means is a wirelessconnection, such as infrared or radio frequency.

The beam controller 240 is operatively coupled to the two-dimensionaltransducer array 210 for varying characteristics and properties of thegenerated acoustic pulses 208. The beam controller 240 is capable ofgenerating a plurality of driver signals 227 that correspond to thenumber of acoustic elements 212 to be activated. The beam controller 240further controls the timing of the respective driver signals 227 appliedto the acoustic elements 212 (i.e. phase shifting), and the resultingacoustic beam 230 is initially generated at a first end 213 of thetwo-dimensional transducer array 210 and advances along a longitudinalaxis-X of the two-dimensional transducer array 210 towards a second end215.

More specifically, when the acoustic beam 230 is initially formed, anumber of the active acoustic elements 212 disposed in the first columnthat is adjacent the first end 213 are actuated by corresponding driversignals 227 from the beam controller 240 simultaneously. After theacoustic elements 212 of the column are activated by the correspondingdriver signals 227, the process repeats itself in the next adjacentcolumn of acoustic elements 212. Activation of the acoustic elements 212in this manner is referred to as beam tractor treading and is used togenerate an acquired three-dimensional volume 214 as shown in FIG. 2. Itis further contemplated that more than one column of acoustic elements212 may be activated by the beam controller 240 simultaneously therebyforming an active aperture including the acoustic beam 230.Advantageously, the beam controller 240 advances the active aperture bya predetermined number of columns to acquire the desired volume.

Alternatively, the beam controller 240 can actuate a number of activeacoustic elements 212 in a number of columns where the number ofacoustic elements 212 activated is less than the number of activeacoustic elements 212 in each of the columns thereby forming a smalleractive aperture and acoustic beam 230. Preferably, the beam controller240 causes the generation of acoustic beam 230 within the activeaperture and the beam controller 240 is adapted to move the activeaperture and the acoustic beam 230 along the row of acoustic elements212. After the active aperture reaches the end of the row of acousticelements 212 at back end portion 217 of the transducer array 210, thebeam controller 240 shifts the acoustic beam 230 and the active apertureby the number of previously activated columns and causes the activeaperture to advance towards a front end portion 216 of the transducerarray 210. By advantageously controlling the motion and direction of theacoustic beam 230 and resultant active aperture, a three-dimensionalvolume is obtainable.

The acoustic pulses 208 are directed towards an acoustic target andportions of the acoustic pulses 208 are reflected towards thetwo-dimensional transducer array 210 as echo signals 206. After eachacoustic element 212 activates to generate the acoustic pulse 208, theacoustic element 212 is capable of receiving the echo signal 206. Thisecho signal 206 contains information relating to the acoustic target andgenerates an output signal 245 from the acoustic element. This outputsignal 245 is communicated through the transmitter 230 and the pulsecontroller 240 to the signal processor 250. In the signal processor 250,the output signal 245 of the acoustic element 212 is transformed byassociated circuitry in the signal processor 250 to generate an imagesignal 255. A display 260 is operatively coupled to the output of thesignal processor 250 for receiving one or more image signals 255 and fortransforming the image signals 255 into a video image. Essentially, thedisplay 260 is capable of displaying data corresponding to the at leastone image signal 255. It is preferred that the display 260 be a videomonitor that is readily viewable by attending personnel.

Turning now to FIG. 2 a, the same or similar components of thepreviously disclosed embodiment are included in the ultrasonic imagingsystem. However, in this embodiment, the acoustic pulse 208 a combinesthe ultrasonic imaging system of FIG. 2 with beam tractor treading asdiscussed hereinabove with beam steering. Beam steering, as previouslydiscussed, occurs when the combination of the transmitter generateddriver signals 225 are coupled and controlled by the beam controller 240a, using phase shifting, to generate the acoustic pulses 208 a from theactivate acoustic elements 212 thereby forming an acoustic beam 230 a.By advantageously combining beam tractor treading and beam steering, athree-dimensional volume 214 a (see FIG. 2 a) having a greater field ofview, and therefore a greater volumetric image, is obtainable.

In this embodiment of the present invention, beam tractor treadinggenerates an acoustic beam 230 a starting with the acoustic elements 212disposed in the column adjacent to a first side 213 of thetwo-dimensional transducer array 210. As before, the transmitter 230 incooperation with the beam controller 240 a causes the active acousticelements 212 to be activated simultaneously in each column to generatethe acoustic beam 230 a. After all the acoustic elements 212 in thecolumn are activated, the next adjacent column of acoustic elements 212is activated. As before, the columns of acoustic elements 212 areactivated in sequence and controllable by the beam controller 240 a Inaddition, the beam controller 240 a phase-shifts the generation of theacoustic pulses 208 a of the activated acoustic elements 212 for “beamsteering.” By advantageously advancing (i.e. beam tractor treading) thephase-shifting of the acoustic beam 230 a (i.e. beam steering), thetwo-dimensional transducer array 210 of the present invention is capableof capturing and displaying the three-dimensional acquired volume image214 a as seen in FIG. 2 a. It is further contemplated that more than onecolumn of acoustic elements 212 may be activated to form the acousticbeam 230 a.

Another exemplary embodiment of the present invention is illustrated inFIG. 3. In this embodiment, an ultrasonic imaging system includes anultrasonic probe 220 with a two-dimensional ultrasonic array 210, a beamcontroller 240 b, a signal processor 250, and a display 260. Similar tothe embodiments of FIGS. 2 and 2 a, the two-dimensional transducer array210 is a generally planar arrangement of acoustic elements 212 where theplurality of acoustic elements 212 is configured and arranged in anumber of rows and columns. It is contemplated that within thetransducer array 210, the number of acoustic elements may include aquantity of passive acoustic elements 212 disposed among the activeacoustic elements 212 (i.e. a sparse array).

Similar to the previous embodiment, the acoustic pulse 208 b is directedtowards an acoustic target and a portion of the acoustic pulse 208 b isreflected towards the two-dimensional transducer array 210 as an echosignal 206 b. After each acoustic element 212 activates to generate theacoustic pulse 208 b, the acoustic element 212 is capable of receivingthe echo signal 206 b. This echo signal 206 b contains informationrelating to the acoustic target and generates an output signal 245 fromthe acoustic element 212. This output signal 245 is communicated throughthe transmitter 230 and the beam controller 240 b to the signalprocessor 250. In the signal processor 250, the output signal 245 of theacoustic element 212 is transformed by associated circuitry in thesignal processor 250 to generate an image signal 255. A display 260 isoperatively coupled to the output of the signal processor 250 forreceiving one or more image signals 255 and for transforming the imagesignals 255 into a video image. Essentially, the display 260 is capableof displaying data corresponding to the at least one image signal 255.It is preferred that the display 260 be a video monitor that is readilyviewable by attending personnel.

Coupled to the two-dimensional transducer array 210 is the beamcontroller 240 using a connecting means 225. Generally, the connectingmeans 225 is a cable having a plurality of conducting elements, such aswires. Alternatively, the connecting means 225 can be a wirelessconnection, such as infrared or radio frequency. In operation, the beamcontroller generates a plurality of driver signals 227 that correspondto the number of acoustic elements 212 to be activated. As previouslydiscussed, each acoustic element 212 is capable of generating anacoustic pulse 208 b or receiving an echo signal 206 b. The beamcontroller 240 controls the generation of the respective driver signals227. In this embodiment, a first column of acoustic elements 212 isdisposed adjacent to a first end 213 of the two-dimensional transducerarray 210.

Advantageously, the beam controller 240 b generates a number of driversignals 227 that activate the active acoustic elements 212 in eachcolumn in a sequential manner. Activating acoustic elements 212 in eachcolumn sequentially, before activating the next adjacent column permitsbeam tractor treading along a longitudinal axis-X of the two-dimensionaltransducer array 210 and a lateral axis-Y of the two-dimensionaltransducer array 210. Further still, the beam controller 240 b, causesthe generated acoustic pulses 206 b to be phase-shifted therebygenerating an acoustic beam 230 b by “beam steering.” By advantageouslycombining beam steering of the acoustic beam 230 b with tractor treadingin both the longitudinal and lateral directions (i.e. rasterizing), theultrasonic imaging system is capable of capturing and displaying anacquired volume image 214 b as illustrated in FIG. 3. It is envisionedthat the transducer array 210 includes acoustic elements 212 that mayinclude a quantity of passive acoustic elements 212 disposed among theactive acoustic elements 212 (i.e. a sparse array).

In an alternative embodiment, an ultrasonic imaging system is shown inFIG. 4 and includes an ultrasonic probe 320 having a two-dimensionaltransducer array 310. The transducer array 310 includes a plurality ofacoustic elements 312 generally arranged in a cylindrical configuration.As in previous embodiments, each acoustic element 312 is formed from asuitable piezoelectric material having the capability to generate anacoustic pulse 308 in response to an input driver signal 327 and toreceive echo signals 306 from an acoustic target to generate an outputsignal 345. The ultrasonic imaging system further includes a beamcontroller 340, a signal processor 350, and a display 360. The beamcontroller 340 is coupled to the two-dimensional transducer array 310 bya connecting means 325 and is capable of generating a number of driversignals 327 that correspond to the number of active acoustic elements312. The connecting means 325 is generally a cable including a pluralityof connecting elements, such as wires. Alternatively, the connectingmeans 325 can be a wireless connection, such as infrared or radiofrequency. Further still, the beam controller is capable ofcommunicating the generated output signals 345 from the acousticelements 312 to the signal processor 350.

Cooperatively coupled to the ultrasonic probe 320 is a beam controller340 for phase shifting the driver signals 327 that generate the acousticpulses 308 and communicating the output signals 345 to the signalprocessor 350. Advantageously, the beam controller 340 generates anumber of acoustic pulses 308 to form an acoustic beam 330 bysimultaneously activating the active acoustic elements 312 in eachcolumn. Operationally, a first column of acoustic elements 312 isadjacent to a first end 313 of the cylindrical two-dimensionaltransducer array 310 where the acoustic elements 312 disposed in thecolumn are activated simultaneously. In a preferred embodiment, as theacoustic elements 312 are activated, the resulting acoustic beam 330 isphase-shifted by the beam controller 340 (i.e. beam steering). After thefirst column has been activated, the beam controller 340 activates thenext adjacent column of acoustic elements 312 to advance the acousticbeam 330 along the longitudinal axis-X of the cylindricaltwo-dimensional transducer array 310. By combining longitudinal tractortreading and beam steering, the ultrasonic imaging system is capable ofcapturing and displaying an acquired volume image 314 as seen in FIG. 4.It is contemplated that multiple columns of acoustic elements 312 may beactivated by the beam controller 340 to produce a larger acoustic beam330 and therefore, a larger active aperture for capturing a largervolume image.

As in the previous embodiments, the acoustic pulses 308 are directedtowards an acoustic target and portions of the acoustic pulses 308 isreflected towards the two-dimensional transducer array 310 as echosignals 306. After each acoustic element 312 activates to generate theacoustic pulse 308, the acoustic element 312 is capable of receiving theecho signal 306. This echo signal 306 contains information relating tothe acoustic target and generates an output signal 345 from the acousticelement 312. This output signal 345 is communicated through thetransmitter 330 and the beam controller 340 to the signal processor 350.In the signal processor 350, the output signal 345 of the acousticelement 312 is transformed by associated circuitry in the signalprocessor 350 to generate an image signal 355. A display 360 isoperatively coupled to the output of the signal processor 350 forreceiving one or more image signals 355 and for transforming the imagesignals 355 into a video image. Essentially, the display 360 is capableof displaying data corresponding to the at least one image signal 355.It is preferred that the display 360 be a video monitor that is readilyviewable by attending personnel. It is contemplated that within thetransducer array 310, the number of acoustic elements may include aquantity of passive acoustic elements 312 disposed among the activeacoustic elements 312 (i.e. a sparse array).

In a further embodiment, an ultrasonic imaging system is illustrated inFIG. 5 and includes an ultrasonic probe 520 with a two-dimensionaltransducer array 510 having a generally convex configuration. Aplurality of acoustic elements 512 is disposed in a number of rows andcolumns. Preferably, the two-dimensional transducer array 510 will havesubstantially equal longitudinal and lateral dimensions. Additionally,the ultrasonic imaging system includes a beam controller 540, a signalprocessor 550, and a display 560. The beam controller 540 is operativelycoupled to the convex two-dimensional transducer array 510 andcommunicates a number of driver signals 527 that correspond to thenumber of acoustic elements 512 to be activated. A connecting means 525operatively couples the beam controller 540 to the convextwo-dimensional transducer array. Typically, the connecting means 525 isa cable having a plurality of conducting elements, such as wires.Alternatively, the connecting means 525 can be a wireless connection,such as infrared or radio frequency.

Similar to the previous embodiments, the acoustic pulse 508 is directedtowards an acoustic target and a portion of the acoustic pulse 508 isreflected towards the two-dimensional transducer array 510 as an echosignal 506. After each acoustic element 512 activates to generate theacoustic pulse 508, the acoustic element 512 is capable of receiving theecho signal 506. This echo signal 506 contains information relating tothe acoustic target and generates an output signal 545 from the acousticelement 512. This output signal 545 is communicated through thetransmitter 530 and the beam controller 540 to the signal processor 550.In the signal processor 550, the output signal 545 of the acousticelement 512 is transformed by associated circuitry in the signalprocessor 550 to generate an image signal 555. A display 560 isoperatively coupled to the output of the signal processor 550 forreceiving one or more image signals 555 and for transforming the imagesignals 555 into a video image. Essentially, the display 560 is capableof displaying data corresponding to the at least one image signal 555.It is preferred that the display 560 be a video monitor that is readilyviewable by attending personnel.

It is preferred that the beam controller 540 is cooperatively coupled tothe beam ultrasonic probe 520 for activating the acoustic pulses 508. Inoperation, the output of the beam controller 540 activates a pluralityof active acoustic elements 512. Initially, the acoustic elements 512 ina first column, that is adjacent to a first end 513 of the convextwo-dimensional transducer array 510, are activated by the driversignals 527 from the beam controller 540. The first acoustic element 512that is activated is the one disposed in the corner between the firstend 513 and a first side 516 of the convex two-dimensional transducerarray 510. The remaining acoustic elements 512 located in the firstcolumn are activated sequentially to generate the acoustic beam 530 andadvance the acoustic beam 530 along a lateral axis-Y. After the lastacoustic element 512 in the first column is activated, the acousticelement 512 disposed in the next adjacent column at a second side 517 ofthe convex two-dimensional transducer array 510 is activated. Theacoustic elements 512 in this column are activated sequentially toadvance the acoustic beam 530 towards the first side 516. The process isrepeated for the remaining columns in the convex two-dimensionaltransducer array 510 and advancing the acoustic beam 530 one or morecolumns at a time (i.e. tractor treading) along a longitudinal axis-X.Further still, the beam controller 540 advantageously phase-shifts theacoustic pulses 508 during the formation of the acoustic beam 530 (i.e.“beam steering”). By advantageously combing beam tractor treading andbeam steering with a convex two-dimensional transducer array 510, theultrasonic imaging system is capable of capturing and displaying thevolume image 514 illustrated in FIG. 5. It is contemplated that withinthe transducer array 510, the number of acoustic elements may include aquantity of passive acoustic elements 512 disposed among the activeacoustic elements 512 (i.e. a sparse array).

Hereinafter disclosed is a method for improving volumetric imaging in anultrasonic imaging apparatus. According to an embodiment of the presentinvention, an ultrasonic probe is provided that includes a plurality ofacoustic elements, a number of which are active acoustic elements, thatare disposed in a number of columns and rows to form a two-dimensionaltransducer array. Advantageously, the two-dimensional transducer arrayis configured and adapted according to one of the previously disclosedembodiments. Further provided is a beam controller that is operativelycoupled via a connecting means to the two-dimensional transducer arraywhere the beam controller is capable of driving at least one of theactive acoustic elements by generating driver signals that generate acorresponding number of acoustic pulses, thereby forming an acousticbeam. Typically, the connecting means is a cable including a pluralityof conducting elements, such as wires. Alternatively, the connectingmeans can be a wireless connection, such as infrared or radio frequency.

The acoustic beam impinges on an acoustic target and generates at leastone echo signal in response. Operatively coupled to the transducer arrayis the beam controller with associated circuitry for controlling therespective driver signals. As discussed hereinabove, the beam controllerphase shifts the driver signals to actuate respective acoustic elementsfor controlling the generated acoustic beam. The beam controller iscapable of generating driver signals for beam steering and beam tractortreading, thereby increasing the field of view for improving thevolumetric imaging capabilities of the two-dimensional transducer array.The echo signals that are reflected from the acoustic target are coupledthrough the beam controller to an input of a signal processor. Theseecho signals are transformed by the signal processor into image signalswhere the display is capable of displaying data corresponding to theimage signals.

In an exemplary method of use, an operator positions the ultrasonicprobe including the two-dimensional transducer array in a region to beimaged. After the ultrasonic probe is positioned, the operator actuatesthe beam controller to generate the desired driver signals for actuatingthe acoustic elements, thereby generating the acoustic beam.Additionally, the beam controller causes the acoustic beam to advance ina desired direction of movement (i.e. beam tractor treading) and/orphase shifting the acoustic pulses (i.e. beam steering). Advantageously,the actuation of the beam controller combines the generation and motionof the acoustic beam. After the acoustic beam impinges on the acoustictarget, echo signals are reflected towards the two-dimensionaltransducer array for capture by the acoustic elements. These echosignals are coupled through the beam controller to the signal processorto generate the image signal. A display receives the image signal anddisplays data corresponding to the image signal as a viewable image tothe operator.

Additionally, a kit for improving the field of view and the volumetricimaging in an ultrasonic imaging system is herein disclosed. In apreferred embodiment, the ultrasonic imaging kit includes at least twoultrasonic probes having associated circuitry where each ultrasonicprobe is configured and adapted to receive an ultrasonic imagingassembly. Each ultrasonic probe includes an ultrasonic transducerassembly having interfaces for interfacing with the associated circuitryof the ultrasonic probe. In a minimum configuration, at least one of theultrasonic transducer assemblies includes a plurality of acousticelements configured and arranged to form a two-dimensional transducerarray. As in previous embodiments, each acoustic element is capable ofproducing an acoustic pulse in response to an inputted driver signal andreceiving an echo signal from an acoustic target.

Coupled via a connecting means to the transducer assembly is a beamcontroller. Generally, the connecting means is a cable having aplurality of connecting elements, such as wires. Alternatively, theconnecting means can be a wireless connection, such as infrared or radiofrequency. The beam controller is capable of generating a plurality ofdriver signals corresponding to the number of acoustic elements to beactuated. Preferably, the beam controller is capable of adjusting thedriver signals, thereby controlling the generation, phase shifting (i.e.beam steering), and motion (i.e. beam tractor treading) of the acousticbeam. A signal processor for receiving the echo signals and formingcorresponding image signals is further included and is coupled to adisplay. The display is capable of displaying data corresponding to theimage signals generated by the signal processor as a viewable image.

The described embodiments of the present invention are intended to beillustrative rather than restrictive, and are not intended to representevery embodiment of the present invention. Various modifications andvariations can be made without departing from the spirit or scope of theinvention as set forth in the following claims both literally and inequivalents recognized in law.

1. An ultrasonic imaging apparatus comprising: an ultrasonic probe; aplurality of acoustic elements configured and arranged to form atwo-dimensional array, said two-dimensional array configured and adaptedto fit within the ultrasonic probe wherein said plurality of acousticelements includes at least two active acoustic elements capable ofgenerating acoustic pulses and/or receiving echo signals; and a beamcontroller coupled to said two-dimensional array, said beam controllercapable of driving the at least two active acoustic elements to producesaid acoustic pulses originating from the two active acoustic elementsfor impinging an acoustic target to generate the echo signals, andhaving associated circuitry configured for controlling directionalmovement of said acoustic pulses by a combination of tractor treadingand beam steering.
 2. The ultrasonic imaging apparatus of claim 1,further including a signal processor coupled to said two-dimensionalarray for processing the echo signal, thereby forming at least one imagesignal.
 3. The ultrasonic imaging apparatus of claim 1, wherein saidtwo-dimensional array is configured and arranged in a substantiallyplanar configuration.
 4. The ultrasonic imaging apparatus of claim 1,wherein said two-dimensional array is configured and arranged in asubstantially cylindrical configuration.
 5. The ultrasonic imagingapparatus of claim 1, wherein said two-dimensional array is configuredand arranged in a substantially convex configuration.
 6. The ultrasonicimaging apparatus of claim 5, wherein said convex configuration includessubstantially equal lateral and longitudinal dimensions.
 7. A method forimproving volumetric imaging in an ultrasonic imaging apparatuscomprising the acts of: providing an ultrasonic probe; providing aplurality of acoustic elements configured and arranged to form atwo-dimensional array, said two-dimensional array configured and adaptedto fit within the ultrasonic probe wherein said plurality of acousticelements includes at least two active acoustic element capable ofgenerating an acoustic pulse originating from the two active acousticelements and/or receiving echo signal; providing a beam controllercoupled to said two-dimensional array, said beam controller capable ofdriving the at least two of active acoustic element to produce saidacoustic pulse for impinging an acoustic target to generate the echosignals and having associated circuitry configured for controllingdirectional movement of said acoustic pulses by a combination of tractortreading and beam steering; and actuating said beam controller togenerate and move said acoustic pulse.
 8. The method of claim 7, furthercomprising the act of providing a signal processor coupled to saidtwo-dimensional array for processing the echo signals, thereby formingat least one image signal.
 9. The method of claim 8, further comprisingthe act of displaying data corresponding to the at least one imagesignal.
 10. The method of claim 7, wherein said two-dimensional array isconfigured and arranged in a substantially planar configuration.
 11. Themethod of claim 7, wherein said two-dimensional array is configured andarranged in a substantially cylindrical configuration.
 12. The method ofclaim 7, wherein said two-dimensional array is configured and arrangedin a substantially convex configuration.
 13. The method of claim 12,wherein said convex configuration includes substantially equal lateraland longitudinal dimensions.
 14. An ultrasonic imaging kit comprising:at least two ultrasonic probes, each having a transducer array andassociated circuitry where each ultrasonic probe is configured anddimensioned for alternative placement within an ultrasonic system, atleast one of a first ultrasonic probe further including a plurality ofacoustic elements configured and arranged to form a two-dimensionalarray, said two-dimensional array configured and adapted to fit withinthe ultrasonic probe wherein said plurality of acoustic elementsincludes at least two active acoustic elements capable of generating anacoustic pulse and/or receiving echo signal; and a beam controllercoupled to the circuitry of the first ultrasonic probe and incommunication with said transducer array disposed within said ultrasonicprobe, said beam controller capable configured for driving the at leasttwo active acoustic elements to produce said acoustic pulses originatingfrom the two active acoustic for impinging an acoustic target togenerate echo signals and having associated circuitry configured forcontrolling directional movement of said acoustic pulses by acombination of tractor treading and beam steering.
 15. The ultrasonicimaging kit of claim 14, further including a signal processor coupled tosaid two-dimensional array for processing the echo signals, therebyforming at least one image signal.
 16. The ultrasonic imaging kit ofclaim 14, wherein said two-dimensional array is configured and arrangedin a substantially planar configuration.
 17. The ultrasonic imaging kitof claim 14, wherein said two-dimensional array is configured andarranged in a substantially cylindrical configuration.
 18. Theultrasonic imaging kit of claim 14, wherein said two-dimensional arrayis configured and arranged in a substantially convex configuration. 19.The ultrasonic imaging kit of claim 18, wherein said convexconfiguration includes substantially equal lateral and longitudinaldimensions.
 20. An ultrasonic imaging system comprising: an ultrasonicprobe; a plurality of acoustic elements configured and arranged to forma two-dimensional array, said two-dimensional array configured andadapted to fit within the ultrasonic probe wherein said plurality ofacoustic elements includes at least two active acoustic elements capableof generating an acoustic pulse and/or receiving an echo signals; and abeam controller coupled to said two-dimensional array, said beamcontroller configured for driving the at least two active acousticelement to produce said acoustic pulses originating from the two activeacoustic for impinging an acoustic target to generate at the echosignal, and having associated circuitry configured for controllingdirectional movement of said acoustic pulse by a combination of tractortreading and beam steering.
 21. The ultrasonic imaging system of claim20, further comprising: a signal processor coupled to saidtwo-dimensional array for processing the echo signals, thereby formingat least one image signal; means for connecting said ultrasonic probe toan ultrasonic imaging apparatus; and means for displaying the at leastone image signal.
 22. The ultrasonic imaging system of claim 20, whereinsaid two-dimensional array is configured and arranged in a substantiallyplanar configuration.
 23. The ultrasonic imaging system of claim 20,wherein said two-dimensional array is configured and arranged in asubstantially cylindrical configuration.
 24. The ultrasonic imagingsystem of claim 20, wherein said two-dimensional array is configured andarranged in a substantially convex configuration.
 25. The ultrasonicimaging system of claim 24, wherein said convex configuration includessubstantially equal lateral and longitudinal dimensions.